The 200 keV Hitachi analytical TEM-STEM is now being applied to a number of problems in biology. The interfacing of the PDP 11/60 computer to the electron microscope has been completed. This enables computer control of data acquisition, including collection of digitized images with bright-field and dark-field current signals as well as pulse counted energy loss and x-ray signals. A satellite computer controls the electron energy loss spectrometer and the x-ray beam deflectors at a rapid rate. Preliminary energy loss and bright field images have been recorded from test samples including thin sections containing calcium. The results demonstrate the feasibility of 128 X 128 pixel elemental mapping at about 30nm resolution using characteristic energy loss edges. The advantages of displaying chemical information combined with morphological information in a composite image has been demonstrated.